GSTM1 and anemia (phenotype): The degree of anemia in patients receiving active anticancer treatment is classified according to the National Cancer Institute (NCI) Common Terminology Criteria for Adverse Effects (CTCAE) (available at https://ctep.cancer.gov/protocoldevelopment/electronic_applications/docs/ctcae_v5_quick_reference_5x7.pdf), ranging from grade 1 or mild (Hb levels < 120/130 g/L in females/males but ≥100 g/L) to grade 4 (Hb levels < 80 g/L and symptoms suggesting a life-threatening condition) (for the detailed classification, see (4).